[CQ-Contest] Skimmer ultimate setup?

Zoli Pitman HA1AG ha1ag at hg6n.hu
Fri Mar 21 04:30:18 EDT 2008


So what is the bottom line here?

Ops who can't do 2r can get skimmer as their 2nd op to do the job what 
distinguishes a 1r op from a 2r op ???

I'm afraid w4pa was right: if it goes on like this cw contesting won't 
be a measure of individual performance anymore.

zoli ha1ag






Pete Smith wrote:
> Hi Dave - I think you are very close.  A few comments below.
> 
> At 03:57 PM 3/20/2008, Dave Hachadorian wrote:
>> I'm trying to figure out how CW Skimmer will ultimately
>> physically tie in to an so2r contest setup. Let me propose a
>> straw man, and then you smart guys can whip it into shape.
>>
>> 1. We use the IF output of the so2r S&P receiver as the
>> source of wideband RF.
> 
> Yes
> 
> 
>> 2. Using an Elecraft K3 as an example, the IF output is at
>> 8.215 Mhz. I hear you need a buffer amp on that output.
>> Somebody makes a "Z10000" that fills the bill.
>>
>> 3. The output of the Z10000 goes to a "Softrock Lite"
>> receiver tuned for 8.215 Mhz. Maybe that frequency needs to
>> be offset from the 8.215 IF to prevent the softrock Lite
>> oscillator from getting into the K3 IF?
> 
> You may not feel the need of the buffer amp (Clifton Laboratories, K8ZOA, 
> www.cliftonlaboratories.com) if you offset the Softrock local oscillator so 
> that it falls outside the roofing filter bandwidth, but it would be a good 
> precaution.  On the radio to which my SoftRock is connected, the local 
> oscillator is S9+40.
> 
> 
>> 4. The stereo audio output of the Softrock Lite goes into a
>> good quality soundcard with a high sampling rate, since we
>> will be dealing with up to 50(?) KHz audio? This soundcard
>> can be the one in the contest computer, since the soundcard
>> is not normally used in CW contesting. If you want to do an
>> audio recording of the entire contest, maybe you need
>> another computer networked to the logging program and do the
>> recording there?
> 
> The soundcard I am currently using is a M-Audio Revolution 5.1 PCU, which 
> cost me about $50.  It records 96 KHz stereo audio, which translates into I 
> and Q channels that the Skimmer software will display as a 96-khz swath of 
> IF bandwidth centered around the center frequency of your SoftRock.  You 
> can get sound cards that go up to 192 KHz, for quite a bit more 
> money.  Look out, though, for cards that have shared mic and line input.
> 
> I use the audio CODEC in my MK2R+ to record contests.  Depending on the 
> BIOS in your computer, you may be able to run both a PCI sound card and 
> your original on-board sound.  I can't, but that's Dell for you...
> 
> 
>> 5. Whichever computer gets the audio, it needs to be running
>> the $70 version of CW Skimmer, and that computer also needs
>> to be running the logging program.
> 
> Yes, although the spots can be passed to the logging program over a local 
> area network, so in theory you could have Skimmer on one PC and the logger 
> on another.  It is worth mentioning here that the CPU demands of the 
> Skimmer, especially in contest circumstances are quite high; this could be 
> disruptive to LPT or COM port CW, depending on your computer and logging 
> software.  I run N1MM and Winkey CW, and experienced absolutely no 
> disruption with Skimmer running on a 2.2 GHz Celeron, even though CPU 
> utilization occasionally hit 100 percent.
> 
> 
>> 6. CW Skimmer outputs spots to the logging program and puts
>> them on the bandmap. I'm a little fuzzy on how CW Skimmer
>> knows the frequency of these spots. Does it look at the rig
>> control frequency of the S&P Radio, or is some other
>> connection required for Skimmer to know the frequency?
> 
> 
> Ah, here's the rub -- Skimmer needs to know what frequency your radio is 
> tuned to, so that it can display the waterfall with real frequencies rather 
> than frequencies relative to the Softrock local oscillator; that, in turn, 
> means that Skimmer needs to be communicating with your radio.  The only 
> means Skimmer currently has for doing this is through VE3NEA's OmniRig 
> interface, which works with many of his programs.
> 
> Unfortunately, Omnirig is not compatible with the rig control used by any 
> of the leading contest logging programs.  I have heard rumors that Writelog 
> can be adapted to permit exchanging frequency data with Skimmer - it may 
> well be that other logging programs can be readily modified to supply radio 
> frequency data through UDP or other means, and that Skimmer will evolve to 
> support such adaptations as they develop - but all of this depends on the 
> software authors.
> 
> I'd suggest reading the section of the Skimmer help file that deals with 
> the "SoftRock with IF" option for further details.
> 
> 
>> 7. Since Skimmer will be connected to the S&P Radio, that
>> radio pretty much has to be dedicated for S&P for the
>> duration of the contest, otherwise Skimmer won't get much
>> listening time because of all the cq-ing if it's connected
>> to the run radio radio?
> 
> Probably right, though I used Skimmer briefly during the Russian DX contest 
> on my run radio - it would simply stop while I was CQing, and then resume 
> copying calls as soon as I started to listen for callers.
> 
> The way I visualize using Skimmer on Sunday in SS is that you would switch 
> the S&P radio to a new band, pause a minute or so while Skimmer works, and 
> then look on your S&P bandmap for Skimmer spots to call.  At that point you 
> would just run up or down the band picking off any fresh meat, and then go 
> on to another band and repeat the process.
> 
> 73, Pete N4ZR 
> 
> _______________________________________________
> CQ-Contest mailing list
> CQ-Contest at contesting.com
> http://lists.contesting.com/mailman/listinfo/cq-contest
> 
> 




More information about the CQ-Contest mailing list